In search of inspiration, Gilliam visited the Tate Gallery:
"I went down to the Tate and they’ve got a huge collection of Victorian Christmas cards so I went through the collection and photocopied things and started moving them around. So the style just developed out of that rather than any planning being involved. I never analysed the stuff, I just did it the quickest, easiest way. And I could use images I really loved.
Continues at Open Culture